Well, first the Earth cooled, and then the dinosaurs came, but they were too big and fat, so they all died and got turned into oil, and then the arabs came and they bought Mercedes Benz. And then Prince Charles started wearing all of Lady Di's clothes.
- Airplane II: The Sequel
Unfortunatelly, drive letters are reminants from the DOS and early Windows days (anything that isn't NT 6.2 kernel based or above, has to have drive letters), so they have to stay for backwards compatibility.
Actually, up until Windows 8, drive letters were required for booting as well (which can be seen in the safe mode boot screen). Windows 8 and above doesn't require them though (can be seen in safe mode with debugging enabled), but they are there and will stay there for a very, very long time. Windows can't just part ways with them, there are just way too many things tied to them... legacy stuff, but legacy stuff that everyone still uses. Like try mounting a network drive without a drive letter, lol ๐... or anything for that matter without a letter, you can't. It's how Windows works. It's so deep into the kernel, that there is no way to remove it without breaking stuff left and right.